Epitope mapping of the monoclonal antibody MM12.10 to external MDR1 P-glycoprotein domain by synthetic peptide scanning and phage display technologies

Epitope mapping of MDR1-P-glycoprotein using specific monoclonal antibodies (mAbs) may help in delineating P-glycoprotein topology and hence in elucid ating the relationship between its structural organization and drug-efflux pump function. In this work, by using synthetic peptide scanning and phage display technologies, the binding sites of the mAb MM12.10, a novel antibod y to intact human multidrug resistant (MDR) cells, were studied, The result s we obtained confirm that two regions localized on the predicted fourth an d sixth loops are indeed external and that MDR1 peptides covering the inner domain of the current 12 transmembrane segment (TMs) model of P-glycoprote in could form part of the MM12.10 epitope.